I. Field of the Invention
The present invention relates to the field of conveyors, and more particularly to the field of conveyors for moving materials longitudinally along a trough. Even more particularly the present invention relates to the field of conveyors for moving chips longitudinally along a conveyor trough using the reciprocating motion of a harpoon.
II. Description of the Prior Art
For many years reciprocating devices have been employed to move chips longitudinally along a trough. The more commonly used devices include a harpoon which moves freely through the chips in a first direction without displacing the chips in the direction of motion, and the harpoon urges the chips to move in the direction of the harpoon when the harpoon is moved in a counter direction. The reciprocating motion of the harpoon is generated by a hydraulic cylinder which alternately pushes and pulls the harpoon. When this method of reciprocating a harpoon is used for a particularly long conveyor system, buckling and binding of the harpoon support is often encountered which limits the weight of chips that can be conveyed and places unusually high horsepower demands on the reciprocating mechanism. Abrasive chips often collect along the rod of the hydraulic cylinder which induces rod wear and eventually causes the leakage of hydraulic fluid and requires frequent replacement of the hydraulic cylinder to keep the system functioning properly. It is to these and other problems that the present invention is addressed.
U.S. Pat. No. 147,523 discloses a log turner for saw mills. This patent discloses a rope or cable operated device which employs a plurality of segmented hooks attached to a cable or rope. When moved in a first direction the hooks engage the periphery of a log to rotate the log, and when moved in a second direction the hooks slide past the log imparting no rotary motion thereto. U.S. Pat. No. 937,192 discloses a lumber loader which is laterally moved by a chain cable or rope and employs a pair of spaced apart pivoted arms which when moved in a first direction fold under a stack of logs to pass therepast. When moved in a second direction, the arms are spring loaded in an upward direction to engage the logs urging them to move in the direction of the rope or cable pulling the arms. U.S. Pat. No. 3,659,701 discloses a cooling conveyor for continuously moving a line of molds from a mold forming machine by means of a continuous chain drive. U.S. Pat. No. 3,738,514 discloses a continuous belt conveyor for conveying bricks from a brick press into an adjacent shuttle car.
None of the above listed U.S. patents disclose nor anticipate a chain or cable driven harpoon for moving machining chips along a trough.